In Europe, most of vineyards are managed under rainfed conditions, where water deficit has become increasingly an issue. The flowering-veraison phenophase represents an important period for vine response to water stress, which is known to depend on variety characteristics, soil and climate conditions. In this paper, we have carried out a retrospective analysis for important European wine regions over 1986–2015, with objectives to assess the mean Crop Water Stress Indicator (CWSI) during flowering-veraison phase, and potential Yield Lose Rate (YLR) due to seasonal cumulative water stress. Moreover, we also investigate if advanced flowering-veraison phase can lead to alleviated CWSI under recent-past conditions, thus contributing to reduced YLR. A process-based grapevine model is employed, which has been extensively calibrated for simulating both flowering and veraison stages using location-specific observations representing 10 different varieties. Subsequently, grid-based modelling is implemented with gridded climate and soil datasets and calibrated phenology parameters. The findings suggest wine regions with higher mean CWSI of flowering-veraison phase tend to have higher potential YLR. However, contrasting patterns are found between wine regions in France-Germany-Luxembourg and Italy-Portugal-Spain. The former tends to have slight-to-moderate drought conditions (CWSI<0.5) along with a negligible-to-moderate YLR (<30%), whereas the latter is found to have severe-to-extreme drought (CWSI>0.5) and substantial YLR (>40%). Wine regions prone to a high drought risk (CWSI>0.75) are also identified, which are concentrated in southern Mediterranean Europe. Advanced flowering-veraison phase over 1986–2015, could have benefited from more spring precipitation and cooler temperatures for wine regions of Italy-Portugal-Spain, leading to reduced mean CWSI and YLR. For those of France-Germany-Luxembourg, this can have reduced flowering-veraison precipitation, but prevalent reductions of YLR are also found, possibly due to shifted phase towards a cooler growing-season with reduced evaporative demands. Our study demonstrates flowering-verasion water deficit is critical for potential yield, which can have different impacts between Central and Southern European wine regions. This phase can be advanced under a warmer climate, thus having important implications for European rainfed vineyards. The overall outcome may provide new insights for appropriate viticultural management of seasonal water deficits under climate change.

在欧洲，大多数葡萄园都是在雨养条件下管理的，缺水已成为一个日益严重的问题。开花转色物候期是葡萄树对水分胁迫作出反应的重要时期，众所周知，这取决于品种特征、土壤和气候条件。在本文中，我们对 1986 年至 2015 年间重要的欧洲葡萄酒产区进行了回顾性分析，目的是评估开花期的平均作物水分胁迫指标 (CWSI) 和潜在的产量损失率 (YLR)季节性累积水资源压力。此外，我们还调查了在过去的条件下，提前开花期是否会导致 CWSI 减轻，从而导致 YLR 降低。采用基于过程的葡萄树模型，它已被广泛校准，用于使用代表 10 种不同品种的特定位置观察来模拟开花和变色阶段。随后，使用网格化的气候和土壤数据集以及校准的物候参数实施基于网格的建模。研究结果表明，开花期平均 CWSI 较高的葡萄酒产区往往具有较高的潜在 YLR。然而，在法国-德国-卢森堡和意大利-葡萄牙-西班牙的葡萄酒产区之间发现了截然不同的模式。前者往往具有轻度至中度干旱条件（CWSI<0.5）以及可忽略不计至中度的 YLR（<30%），而后者被发现具有重度至极端干旱（CWSI>0.5）和大量的 YLR (>40%)。还确定了容易发生高干旱风险（CWSI>0.75）的葡萄酒产区，集中在地中海南部的欧洲。1986 年至 2015 年的开花期提前，可能受益于意大利-葡萄牙-西班牙葡萄酒产区春季降水增多和温度降低，导致平均 CWSI 和 YLR 降低。对于法国-德国-卢森堡的植物，这可能会减少开花期的降水量，但也发现 YLR 普遍减少，这可能是由于蒸发需求减少而转向较凉爽的生长季节。我们的研究表明，开花期缺水对潜在产量至关重要，这会对中欧和南欧葡萄酒产区产生不同的影响。这一阶段可以在温暖的气候下进行，因此对欧洲雨养葡萄园具有重要意义。